From e079ceb9c3d2e47ff4d00129ad37aa79fb9f421e Mon Sep 17 00:00:00 2001
From: daraelmin <daraelmin@gmail.com>
Date: Fri, 26 Feb 2021 08:51:01 +0100
Subject: [PATCH 1/2] Fix #16420 undefined  $model_mail_selected_id

Set $model_mail_selected_id to 0 when it is undefined
---
 htdocs/core/class/html.formmail.class.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/htdocs/core/class/html.formmail.class.php b/htdocs/core/class/html.formmail.class.php
index e8b291ebfca..9c98a69d14a 100644
--- a/htdocs/core/class/html.formmail.class.php
+++ b/htdocs/core/class/html.formmail.class.php
@@ -488,7 +488,7 @@ class FormMail extends Form
 
 			// Zone to select email template
 			if (count($modelmail_array) > 0) {
-				$model_mail_selected_id = GETPOSTISSET('modelmailselected') ? GETPOST('modelmailselected', 'int') : $arraydefaultmessage->id;
+				$model_mail_selected_id = GETPOSTISSET('modelmailselected') ? GETPOST('modelmailselected', 'int') : ( ($arraydefaultmessage->id) ?  $arraydefaultmessage->id : 0 );
 
 				// If list of template is filled
 				$out .= '<div class="center" style="padding: 0px 0 12px 0">'."\n";

From e7ae2e65d7790afcf547da58bffc73dd14c57480 Mon Sep 17 00:00:00 2001
From: Laurent Destailleur <eldy@destailleur.fr>
Date: Fri, 26 Feb 2021 10:33:49 +0100
Subject: [PATCH 2/2] Update html.formmail.class.php

---
 htdocs/core/class/html.formmail.class.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/htdocs/core/class/html.formmail.class.php b/htdocs/core/class/html.formmail.class.php
index 9c98a69d14a..4898e8d5872 100644
--- a/htdocs/core/class/html.formmail.class.php
+++ b/htdocs/core/class/html.formmail.class.php
@@ -488,7 +488,7 @@ class FormMail extends Form
 
 			// Zone to select email template
 			if (count($modelmail_array) > 0) {
-				$model_mail_selected_id = GETPOSTISSET('modelmailselected') ? GETPOST('modelmailselected', 'int') : ( ($arraydefaultmessage->id) ?  $arraydefaultmessage->id : 0 );
+				$model_mail_selected_id = GETPOSTISSET('modelmailselected') ? GETPOST('modelmailselected', 'int') : ($arraydefaultmessage->id > 0 ?  $arraydefaultmessage->id : 0);
 
 				// If list of template is filled
 				$out .= '<div class="center" style="padding: 0px 0 12px 0">'."\n";